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Near-infrared (NIR) spectrophotometers with different optical arrangements were used to measure the diffusely reflected electromagnetic radiation of different types of food additives in polyethylene (PE) foils. Eight compounds, frequently used in food process – but also in other industries –, were measured by different NIR spectrophotometers. The detected (‘as is’) and mathematically transformed (by scatter correction, second derivative combined with smoothing) NIR spectra were processed with multivariate data analysis (MDA). In this matter, unsupervised methods like principal component analysis (PCA) and cluster analysis (CA) were used, which techniques do not require prior information and reference measurements. The aim of the present study was to distinguish food additives by the help of the applied chemometric methods based on NIR spectra detected via the PE foils. Results indicated that distinction of different food additives and compounds with NIR methods is possible not only with the conventional sample preparations and handlings, but also without breaking the packaging.

Open access

Abstract

Soybean seeds were germinated on an industrial scale after soaking for 0–56 h to produce a special additive for food industrial use. The germination process of three soybean varieties was monitored with near-infrared (NIR) spectroscopy based on changes in the amount, status, or character of the water. This paper evaluates the “waterless” NIR spectra of sound, germinated, and heat treated seeds to try to follow the fine details of the germination process. The germination process was analysed with the help of cluster analysis (CA), principal component analysis (PCA), and polar qualification system (PQS) as statistical and chemometric methods. PCA proved to be the most sensitive spectrum evaluation method to follow the fine details of germination. The applied NIR method is suitable for non-destructively, real-time monitoring of the non-linear nature of germination.

Open access
Community Ecology
Authors:
Z. Kemencei
,
R. Farkas
,
B. Páll-Gergely
,
F. Vilisics
,
A. Nagy
,
E. Hornung
, and
P. Sólymos

We determined microhabitat associations for 39 land snail species based on multimodel inference and generalized linear mixed models using a comprehensive and micro-scale data set from the Aggtelek Karst Area, Hungary. Patterns of microhabitat associations were highly nested among microhabitat types (litter, live trees, dead wood, rock) with high number of specialist species in dead wood and in rock microhabitats. Species composition was highly predictable in these microhabitats as opposed to live tree and litter faunas. Species richness was affected by microhabitat, topographic factors and local moisture conditions. Species richness in dead wood and rock microhabitats remained high irrespective of the topographic effects as opposed to litter and live tree microhabitats, where richness decreased with drier microhabitat conditions due to topography. Our results imply that consideration of topographic factors and microhabitat quality as part of coarse filter conservation measures could be beneficial to local land snail populations in the face of changing climate and disturbance regimes.

Restricted access
Acta Alimentaria
Authors:
M. Hódsági
,
Á. Jámbor
,
E. Juhász
,
S. Gergely
,
T. Gelencsér
, and
A. Salgó

Resistant starches (RSs) are broadly investigated as appropriate additives in starch-based products due to their well-known and proved health benefits. However, it was shown in previous studies that these starches are sensitive of the different heat treatments used in the food processing, which can cause changes, especially in the resistance. There is an increasing trend to use microwave (MW) energy in food processing; therefore, our aim was to investigate the changes of RSs compared to native starches caused by MW heating. Maize, wheat, RS2 and RS4 starches were MW-treated according to a 2×2 experimental design (300 and 600 W of power, 30 and 150 s of time). The changes of in vitro digestibility, rheological properties (rapid visco analyser, RVA) and near infrared (NIR) spectroscopic characteristic were studied. Two spectrophotometers were applied (dispersive and Fourier-transform (FT)) to compare their sensitivity in the analysis of the MW-treated starches.Results showed that the digestibility of starches did not show any tendencies when increasing the microwave energy of treatments, the characteristics of the kinetic curves remained unchanged. The RVA analysis showed that the RSs did not gelatinize after the heat-treatments. The MW heating weakened the rheological properties of all starches. The NIR analysis was the most sensitive device for the detection of the effects of MW treatments. The analysis of the most characteristic carbohydrate regions (2080–2130 and 2270–2290 nm) highlighted structural alterations of the starches; moreover, the dispersive spectrophotometer was found to be more sensitive in the analysis of starches than the FT-one.

Restricted access
Cereal Research Communications
Authors:
T. Abonyi
,
S. Tömösközi
,
M. Budai
,
Sz. Gergely
,
É. Scholz
,
D. Lásztity
, and
R. Lásztity

The proteins that form gluten of a winter wheat cultivar, Ukrainka (HMW-GS composition 1, 7+8, 5+10) grown in Hungary and harvested in the year 2006, was investigated during grain development. The formation of gluten, its protein fractions and composition of polymeric fraction, were followed starting at the 12 th day after anthesis (DAA) to the 52 nd .Gluten formation was first observed (manual method of determination) only 20–25 days after anthesis and its quantity increased rapidly during the next period of grain development. The gluten was separated to a fraction extractable with SDS-phosphate buffer and another fraction, unextractable by this buffer. An increase in the ratio of unextractable polymeric protein (UPP)/soluble protein fraction was observed during grain development. As expected, gliadin was the main component of the soluble fraction and glutenin that of the insoluble one. HMW monomers were detected in unreduced fractions in small quantities only until 30 th DAA. RP-HPLC of reduced gluten fractions showed a slight increase of the ratio HMW/LMW with days after anthesis.An increase of relative viscosity of gluten solutions during grain development was also observed as a sign of polymerization of glutenin subunits and consequently an increase in average molecular weight of glutenin.

Restricted access
Acta Botanica Hungarica
Authors:
J. Csiky
,
L. Balogh
,
I. Dancza
,
F. Gyulai
,
G. Jakab
,
G. Király
,
É. Lehoczky
,
A. Mesterházy
,
P. Pósa
, and
T. Wirth

As part of the PADAPT project, the authors compiled the invasion biological database of the alien vascular flora of Hungary, which contains the nativeness, residence time, introduc- tion mode and invasion status of 878 alien or cryptogenic taxa. In the absence of adequate evidence, the classification of some species was only possible into uncertain, transitional cat- egories. The definitions of most categories are compatible with several international termi- nologies, but are primarily based on Central European traditions. Of the 560 taxa that have already been naturalised in Hungary, 85 are invasive, and 22 of them are transformer alien vascular plants. Only 5 of these transformers are included in the European list of Invasive Alien Species of Union concern (Ailanthus altissima, Asclepias syriaca, Elodea nuttallii, Heracleum mantegazzianum and H. sosnowskyi), which require uniform preventive interventions and treatments throughout the continent, while the rest of transformers in Hungary (e.g., Robinia pseudoacacia, Fallopia × bohemica and Solidago gigantea) draw attention to the unique, local and/ or regional invasion biological situation of the Pannonian Basin and Central Europe.

Open access